Due to new technological advances in automotive engineering, both mechanical and electronic, and with the incorporation of new vehicle propulsion systems (GNC, LNG, Autogas, hybrids, electrics and hydrogen) we have to constantly update our knowledge to ensure, as far as possible, our safety and that of the people that we help when we are called to a traffic accident. To do this, we need to adapt to the conditions that arise in the new scenarios where we have to act, and one of the fields where this update is necessary is in the stabilization of vehicles in an emergency situation.
When talking about stabilization, we have to ensure that it is done so that the vehicles do not move from where they have been found, and if it is necessary to move them then this is done with control. This will ensure the safety of the first responders and that of the people inside the cars.
On the Internet you can see examples of vehicles burning which are not in a stable position; they are moving and hence creating a much greater danger than the fire of the car itself.
Here is a link where you can see an example of what I mean (you can also view by scanning the QR code): https://www.youtube.com/watch?v=ISBv4zlfyoI
As you can see in the video, at first, the principal danger is the fire of the car. But the fire becomes secondary when the vehicle starts moving with the potential to run over a person or start a secondary fire when an object stops the car’s movement.
Another example of how a vehicle can be moved after an accident can be seen in the following video: https://www.youtube.com/watch?v=LU4G_PmqJ0c
A crashed vehicle that is still running can be a danger for several reasons, for example when inadvertently pressing the accelerator pedal. In the case of this last video, the car is moved intentionally by the driver when he wants to flee from the crash site, creating additional danger with this actions.
If we review the Emergency Response Guides (ERGs) of certain hybrid and electric car manufacturers such as Tesla, Lexus or Toyota, they tell us to chock the road wheels in case of emergency, since electric motors are not heard when the vehicle is stopped and you cannot know, at first, whether it is energized or not. This can create the danger that it may move for any reason and create a high-risk situation for rescuers trying help the occupants.
Therefore, to the stabilization of damaged or burned vehicles we must add a safety stabilization, which is already carried out in many cases, that allows us to work with certain safety guarantees during the first moments of the automotive emergency.
Types of vehicle stabilization
1. Safety immobilization:
In this section, we consider two scenarios differentiated by the variety of dangers that each presents in the emergency, and which firefighters have faced on multiple occasions:
Vehicles on fire
As we have seen above, a burning vehicle can move for several reasons and therefore its immobilization is necessary. It can also be that when faced with a fire in an electric vehicle, at first we do not know if the motor is energized as is cannot be heard. The optimal way to stabilize a burning car is as follows depending on where it is on fire:
It is important that we get close in order to work on one of these burning vehicles, so we must first immobilize it with chocks to prevent uncontrolled movement. It should be noted that we cannot always approach the car during the first moments of intervention, mainly because of the heat load that can be released and by the dangers of projectile objects, especially if the propulsion system is LPG or CNG. But once the risks subside and the fire is controlled we can approach the car and immobilize it to avoid unwanted movements.
In vehicle accidents, Tesla, Toyota and Lexus tell us that their cars must be treated in a particular way before acting on them. This is because electric motors do not make noise and, in principle, it is not known whether they are in energized or not. The Emergency Response Guides of these car companies advise us to chock the wheels of these cars as a safety measure in emergency situations. We must make sure that the chocks have sufficient height so that if the vehicle tries to move, it is prevented from doing so.
Vehicle inside overturning
On initial approach, the greatest instability presented by a car in this position is the possibility of rotation towards the roof. This gives us one of the first risks we must face when it comes to making a rescue. To perform a safety stabilization, a chock (ladder or other) must be put on the B-post to block this possible rotation. The stabilizing element must be the right size to stay in the gap created between the B-post and the ground and prevent movement.
This will give rescuers the required safety to be able to board the car and also ensure no further injuries to the people inside.
Vehicle in total rollover
In this position, during an initial approach, the greatest risk for rescuers and the people inside is the instability of the vehicle, which has the potential to overbalance both forward and backward.
In total overturning, depending on how the car is resting, put a chock under the roof and another under the bonnet/hood to avoid any rocking motion and guarantee safety for boarding firefighters.
The position we see in the drawing is where a vehicle presents the most instability, and therefore it is necessary to stabilize it safely. We will chock it by the C-post and the bonnet/hood. At this point, we must consider that a primary and secondary stabilization must be done, and so the necessary space must be left when placing the safety chocks.
Other forms of safety stabilization
Sometimes, in the first few moments, we find cars in certain positions that force us to eliminate the immediate danger they present for reasons of security for the rescue. This is especially true in the case where a crashed car is on the edge of a ravine, embankment or bridge where the first need is to secure the vehicle to avoid the high risk of it moving suddenly.
The anchor points can be several, and we must always consider the possible forces generated during the stabilization and ensure that the anchor points have sufficient capacity to withstand these. Trees, our own trucks, houses, lamp posts etc. can serve as anchors to neutralize the danger, both for rescuers and occupants, presented by slippage during those initial moments. The knowledge of our tools, their capabilities and limitations will give us the ability to perform the rescue efficiently and effectively shorten the time to rescue the occupants.
We must keep in mind that sometimes, once primary and secondary stabilization has been established, these security stabilization points can be changed if they no longer fulfil the task for which they were initially placed, or if they prevent or make it difficult for us to carry out the extraction.
2. Emergency stabilization
When we are in an accident, sometimes the injured people need medical attention immediately, and even urgent removal, due to the nature of their injuries to guarantee their life. To do this, the fire crew will hold the vehicle structure and try to immobilize it as much as possible allowing a team member or medical responder to access the occupants to treat their injuries or perform an emergency extraction. Examples are PCR accidents, massive bleeding, etc.
3. Primary and secondary stabilization
Depending on the complexity of stabilizing the vehicle or vehicles involved in a traffic accident, the stabilizations are divided into primary and secondary. Primary stabilization is the minimum stabilization that prevents the vehicle from moving and allow a rescuer to enter the car to apply the necessary medical care that can be performed at that time.
Secondary stabilization is a complement or continuation of the primary, whose function is to secure the vehicle to carry out the release work safely for both rescuers and occupants.
Re-stabilization: after and every time the vehicle is moved or its centre of gravity is shifted, a check of such stabilization must be carried out so that it does not lose its effectiveness. Currently on the market there are devices that enable this to be done automatically.
In a complex accident the optimal realization of a two-car stabilization would be performed sequentially where one would be complemented by the previous one. Here is an example of the three stabilizations to be performed: safety, primary and secondary.
4. Dynamic stabilization
Having performed the safety, primary and secondary stabilization, it may be necessary to modify the vehicle stabilization to enable the rescue of occupants. This usually occurs if the lifting of vehicles necessary for the rescue of people, also called emergency elevation. Here it is necessary to adapt the stabilizing points to the height reached by the car, or allow these points to move at the same time as the car or heavy vehicle rises.
5. Precautions to be taken during stabilization
When stabilizing a crashed vehicle, we must consider some safety warnings.
If they are diesel or petrol cars, we take care not to place the stabilizing elements on the tanks or fuel lines, depending on the position of the car.
If they are alternative-energy cars, we should follow the Emergency Response Guides of automakers. In electric and hybrid cars such as Telsa, Toyota or Lexus, the guides specify where the stabilizing elements are to be placed.
For example, Tesla tells us that, in an emergency, its cars must be stabilized using specific areas of the vehicle. The following drawing is taken directly from the rescue sheet of a Tesla Model 3, but this representation applies to any vehicle of this brand.
Also, Toyota and Lexus advise us where to stabilize their cars. In the drawings you can see the stabilization points for a 2012 Prius Hybrid and a 2007 Lexus GS450h.
Both drawings are drawn from the Emergency Response Guides that both Toyota and Lexus have published after assessing the exact stabilization points.
When stabilizing gas vehicles, we must consider both the tanks and the fuel lines that carry the gas underneath the car. In the images above you can see an example of where both elements are located and where they pass through. And as you can see, they are not always mounted in the same position, and so special care must be taken not to put stabilizers in these areas, as they could damage the pipes or pressurized tanks and cause a gas leak.
And while it may seem anecdotal, there are already car companies, such as Hyundai and BMW, that will soon launch Hydrogen propulsion vehicles like the one we can see in the following drawing. The Rescue Sheets and Emergency Response Guides of these cars already exist. It is very important to know where the different gas tanks are housed, the passage of the pipes and where the fuel cell is housed, when it comes to being able to make a rescue intervention in traffic accidents involving these vehicles.
6. Accident car transfer
Today and more and more frequently, we can see in the Emergency Response Guides that the different car manufacturers tell us how to tow their crashed vehicles.
In the different drawings shown you can see that each brand and car has its own towing system.
For more information, email [email protected]
- Basic manual rescue in APRAT and DGT traffic accidents.
- Basic IVASPE manual for new ingress firefighters.
- Tesla, Toyota, Lexus, and Honda Emergency Response Guides.
- Software CRASH RECOVERY SYSTEM de la empresa MODITETCH RESCUE SOLUTIONS.